Shader semantics supported by Viewport 2.0

The following semantics are recognized and supported for use with shaders in Viewport 2.0. They can be used when authoring full effects which are accessed as MShaderInstance objects using the MShaderManager class. They may also be applied to the parameters of fragments which are registered using MFragmentManager.

Note: The dx11Shader.mll and glslShader.mll plug-ins are both MPxShaderOverrides. Therefore, each must parse the effects to determine and bind the semantics manually. By comparison, both the fragment system and MShaderInstance do all this automatically; however, they are both also more restrictive.

The world co-ordinate system can be further divided into different locales, each with a different origin. A node can then be specified in any of these locales. This allows the node position to be made with greater precision than if it were defined in the world co-ordinate system.

All matrices that belong to the FrameLocale group are re-applied when the locale of a current node is different from the locale of a previous node. At render time, camera and lights are transformed into the current node's locale space so that the object, the camera, and the lights are all represented in the same local co-ordinate space and can be stored and represented with single precision floating point values.

Semantic	Usage	Type	Group
World	World transformation	Matrix	Item FL
WorldTranspose	World transformation, transposed	Matrix	Item FL
WorldInverse	World transformation, inverted	Matrix	Item FL
WorldInverseTranspose	World transformation, inverted and transposed	Matrix	Item FL
PreviousWorld	Previous world transformation	Matrix	Item
NextWorld	Next world transformation	Matrix	Item
View	View transformation	Matrix	FrameLocale
ViewTranspose	View transformation, transposed	Matrix	FrameLocale
ViewInverse	View transformation, inverted	Matrix	FrameLocale
ViewInverseTranspose	View transformation, inverted and transposed	Matrix	FrameLocale
Projection	Projection transformation	Matrix	Frame
ProjectionTranspose	Projection transformation, transposed	Matrix	Frame
ProjectionInverse	Projection transformation, inverted	Matrix	Frame
ProjectionInverseTranspose	Projection transformation, inverted and transposed	Matrix	Frame
ProjectionZSense	Denotes whether the projection matrix flips the Z component of a point when transformed: if so, -1.0; otherwise 1.0.	Float	Frame
WorldView	World-view transformation	Matrix	Item FL
WorldViewTranspose	World-view transformation, transposed	Matrix	Item FL
WorldViewInverse	World-view transformation, inverted	Matrix	Item FL
WorldViewInverseTranspose	World-view transformation, inverted and transposed	Matrix	Item FL
WorldLocaleOrigin	Apply an offset to the locale transformation matrix to obtain the true (global) world transformation matrix. Applying this offset can result in a lack of precision in cases where double precision is required to represent an accurate position in large coordinate systems.	Float3	FrameLocale
ViewProjection	View-projection transformation	Matrix	FrameLocale
ViewProjectionTranspose	View-projection transformation, transposed	Matrix	FrameLocale
ViewProjectionInverse	View-projection transformation, inverted	Matrix	FrameLocale
ViewProjectionInverseTranspose	View-projection transformation, inverted and transposed	Matrix	FrameLocale
PreviousViewProjection	Previous view-projection transformation	Matrix	FrameLocale
WorldViewProjection	World-view-projection transformation	Matrix	Item FL
WorldViewProjectionTranspose	World-view-projection transformation, transposed	Matrix	Item FL
WorldViewProjectionInverse	World-view-projection transformation, inverted	Matrix	Item FL
WorldViewProjectionInverseTranspose	World-view-projection transformation, inverted and transposed	Matrix	Item FL
The following are MultiDraw versions of other semantics, used as alternates for rendering MultiDraw consolidation if MPxShaderOverride::supportsMultiDraw() is overridden to return true.
WorldMD	MultiDraw array of World transformation	Matrix[64]	Item FL
WorldTMD	MultiDraw array of World transformation, transposed	Matrix[64]	Item FL
WorldIMD	MultiDraw array of World transformation, inverted	Matrix[64]	Item FL
WorldITMD	MultiDraw array of World transformation, inverted and transposed	Matrix[64]	Item FL
WorldViewMD	MultiDraw array of World-view transformation	Matrix[64]	Item FL
WorldViewTMD	MultiDraw array of World-view transformation, transposed	Matrix[64]	Item FL
WorldViewIMD	MultiDraw array of World-view transformation, inverted	Matrix[64]	Item FL
WorldViewITMD	MultiDraw array of World-view transformation, inverted and transposed	Matrix[64]	Item FL
WorldViewProjMD	MultiDraw array of World-view-projection transformation	Matrix[64]	Item FL
WorldViewProjTMD	MultiDraw array of World-view-projection transformation, transposed	Matrix[64]	Item FL
WorldViewProjIMD	MultiDraw array of World-view-projection transformation, inverted	Matrix[64]	Item FL
WorldViewProjITMD	MultiDraw array of World-view-projection transformation, inverted and transposed	Matrix[64]	Item FL
ViewDirection	World-space direction of the view (camera)	Float3	FrameLocale
ViewPosition	World-space position of the view (camera)	Float3	FrameLocale
LocalViewer	Denotes whether a local or non-local view direction is to be used	Bool	Frame
IsOrthoGraphic	Denotes whether the projection matrix is orthographic	Bool	Frame
ViewportPixelSize	Dimensions of the current viewport in pixels, width and height	Float2	Frame
ClippingPlanes	The coefficients of active clipping planes, one float4 per plane	Float4 Array	Clipping
ClippingPlaneCount	The number of active clipping planes	Int	Clipping
NearClipPlane	The camera’s near clipping plane	Float	Frame
Time AnimationTime Sas.Time.Now	Time in seconds Note: Only applicable to shading overrides created using an MPxShaderOverride. The MPxShaderOverride must support auto-binding of MUniformParameters to the shader uniform parameters. That is, the MPxShaderOverride must create an MUniformParameter for each uniform parameter, retrieve each MUniformParameter value based on its associated semantic, and bind this value to the shader uniform parameter. This is automatically done by the dx11Shader and glslShader plug-ins. In addition, Time and Frame are only available when the effects file is loaded from the glslShader plug-in.	Float	Frame
Frame FrameNumber	Frame in frame units Note: Only applicable to shading overrides created using an MPxShaderOverride. The MPxShaderOverride must support auto-binding of MUniformParameters to the shader uniform parameters. That is, the MPxShaderOverride must create an MUniformParameter for each uniform parameter, retrieve each MUniformParameter value based on its associated semantic, and bind this value to the shader uniform parameter. This is automatically done by the dx11Shader and glslShader plug-ins.	Int	Frame
AlphaTestFunction	The alpha test comparison function 1 = Never 2 = Less 3 = Equal 4 = Less or Equal 5 = Greater 6 = Not Equal 7 = Greater or Equal 8 = Always	Int	Alpha Test
AlphaTestReference	The alpha test reference value, in the range of (0.0, 1.0)	Float	Alpha Test
RelativeViewportDimensions	Specifies relative viewport dimensions	Float2	Frame
MayaReceivesShadowOn	Denotes whether the object receives shadows	Bool	Item
EnableXRayComp	Denotes whether xray component mode is enabled	Bool	Frame
MayaViewportModes	Viewport modes 0 = Does not contain bounding box 1 = Contains bounding box	Int	Frame
FogEnabled	Denotes whether hardware fog is enabled	Bool	Frame
FogMode	Hardware fog falloff mode 0 = Linear 1 = Exponential 2 = Exponential-squared	Int	Frame
FogStart	Hardware fog start z-distance in view space	Float	Frame
FogEnd	Hardware fog end z-distance in view space	Float	Frame
FogDensity	Hardware fog density	Float	Frame
FogColor	Hardware fog color	Float4	Frame

Note: ^FL denotes that the semantic is also frame locale dependant.